The present invention relates to a printer control device and a printer apparatus equipped with a printer control device to receive print data from external device and create the print data into image data, specifically apparatuses having plural input ports for print data.
In the recent years, printer apparatuses have had plural input ports such as parallel interfaces, USB (Universal Serial Bus) and LAN (Local Area Network) to conform wide variety of interfacing methods.
Even though plural input ports are provided in the apparatus as explained above, there are cases when a bottle neck occurs such as when processes in the printer cannot handle the plural concurrent input data from the plural input ports, an external device from which the print data are issued, cannot send a print data for a long time.
Consequently, a printer apparatus capable of handling concurrent input data from plural input ports featuring a receiving data processing section, a receiving buffer memory and an image creator to analyze and transform receiving data into image data, is proposed for the each input port. (Refer to patent reference No. 1)
[Patent Reference No. 1]
                Japanese Patent Application Publication No. HEU 11-20242.        
It becomes a cost factor to provide the buffer memory and the image creator for each input port, since a configuration of the printer apparatus becomes a major unit. Even though the receiving buffer memory is provided for each input port, in the case of complicated print data, which require more time to be created into image data, and as it continues then the receiving buffer memory eventually reaches its capacity and the receiving function is interrupted due to such a bottleneck. In order to prevent the printer apparatus from reaching the bottleneck, it was necessary to increase memory capacity of the receiving buffer memory. Further, there was a problem that the cost of the printer apparatus eventually rises when the receiving buffer memory is comprised of high-speed access semiconductor memories.